Boiler construction



W. J. lMCALLISTER v BOILER CONSTRUCTION Filed DeC. 3l, 1937 ,45 like solids carried by the flames will slide koif of dinary tank steel. 45

" the tubes because of their streamlined contour A second pair of smaller vertical steel plates I and the lack of aY surface on which to collect. and I6 having arcuate top portions I'I is mounted Patented oct. 31, 1939 2,178,376'

UNITED srares eATjENT orties 2,178,376 Bomen Vcoits'inncfrioN William J. McAllister, Oak'lark, Ill.

Application December 31, 1937, Serial No. 182,788

' 3 Claims. (C1. 122-154) This invention relates to boilers and more A further object of this invention is to prospecically relates to all-steel water tube boilers vide a combustion chamber for boilers that is having streamlined, tear-drop type water tubes. entirely surrounded by water.

The boilers of this inventionl are especially Another object of this invention is to provide 5 adapted forl domestic heating andl can be fired a hollow baille in combustion chambers of boilers .5, with gas, oil, coal, or any other fuel. Thecomin communication with the water space of the bustion chamber provided by thev boiler conboiler. struction of this invention is readily adapted A further object of this invention is to provide to receive any type of firing means and therean all-steel boiler construction composed of 10 fore the boiler construction has universal apnested rinner and outer shells defining water 10 plication. spaces entirely around the combustion chamber The boilers of this invention comprise nested of the boiler and having streamlined water tubes shells defining water legs entirely surrounding in communication with said spaces extending the combustion chamber. A baille, of hollow across the combustion chamber. l5 construction,is provided in the combustion cham- Another object of this invention is to provide 15 ber and has the interior thereof in communiin a boiler construction a natural trap for solid cation with the wat-er legs between the nested material entrained in gases leaving the boiler. shells. A smoke outlet is provided at the rear Other and further objects of this invention will of the combustion chamber behind the baffle. become apparent to those skilled in the art from Water tubes extend through the combustion the following detailed description of the annexed 2Q chamber above the baffle therein and are welded sheet of drawings which l discloses a `preferred' 4 at their ends to the inner shell to communiembodiment of the invention'. cate with the spaces between the shells. On the drawing: l

These water tubes are streamlined to have Figure 1 is an isometric view of a boiler acextensive contact with llames passing therecording to this invention, with parts broken 25 around. The llames travel from the fuel bed or away and shown in cross section to illustrate the burner head in front of the baille upwardly construction of the boiler.

around the water tubes, over the baille and down Figure 2 is an enlarged fragmentary cross-secto the smoke outlet. This sinueus path of the tional View taken along the line II-II of Fig- 39 flames makes possible extensive contact with the ure 1. 30 water tubes and with the inner shell thereby Figure 3 is a fragmentary cross-sectional view effecting good heat transfer between the llames taken along the lineIII-III of Figure 1.

and the water to be generated into steam. Since Figure 4 is a diagrammatic View showing flame the llames travel downwardly to the smoke outcontact with a streamlined water tube accordlet which is spaced behind the baille, soot, ily ing to this invention as compared with a cylin- 35 ash or the like solids entrained with the flames drical water tube. can be deposited in a collection chamber provided As shown on the drawing: between the baiile and the smoke outlet. As a In Figure 1k the refelele numeral IIJ desigresult, such solid materials will not be discharged nates a boiler comprising outer, front and rear 40 through the stack. y vertical steel plates II and I2 having arcuate 40 The streamlined water tubes, besides provid-. top portions I3. An outer crown sheet I4 is ing for extensive contactr between the llames welded at its ends to the plates II and I2 and and the tubes to effect a'good heat transfer, forms with the plates the outer shell of the are also self-cleaning since soot, y ash or the boiler. This shell is preferably composed of or- It is then an object of; this invention to proin spaced opposed relation to the outery plates II vide boiler constructionsk having streamlined and I2. The plates I5 and I6 terminate above tubes for effecting goed heat transfer between the bottoms of the plates II and I2 and have 50 the heating media and the material to be heated. outturned flanges such as I8 along their bottom Another object of this invention is to providev edges. These flanges I8 are welded to the plates boiler `constructions having streamlined water II and I2 respectively. tubes extending through the combustion cham- A crown sheet I9 extends between the plates bers thereof. I5 and I6 and is welded to the plates at its ends. 55

The crown sheet I9 has outturned flanges 20 along the bottoms thereof which ilanges are welded to the sides of the outer crown sheet I4.

The inner plates I5 and I6 together with the inner crown sheet I9, deilne the inner shell of the boiler. This inner shell is in spaced relation from the outer shell and provides a Water chamber 2| entirely surrounding the combustion chamber 22 of the boiler. This chamber 2| is composed of a front water leg 2Ia between the plates II and I5, a rear Water leg 2lb between the plates I2 and I6, side water legs 2Ic between the sides of the crown sheets |4 and I9, and a top Water leg and steam space 2Id between the tops of the crown sheets I9 and I4.

'I'he inner shell is preferably composed of flange steel.

A hollow vertical baille 23 is mounted in the combustion chamber 22 and has the interior thereof in communication with the water legs 2 Ic at the sides of the boiler. The baille 23 is welded to the sides of the inner crown sheet I9 and thus provides a further water leg 24 in the combustion chamber 22.

'I'he baille 23 is mounted intermediate the front and rear inner plates I5 and I6.

The top 25 of the baille 23 is spaced below the top of the crown sheet I9.

A plurality of streamlined water tubes 25 extend horizontally through the combustion chamber 22 above the top 25 of the baille 23 and are welded at their ends through the end plates I5 and I6, so that the interiors of the tubes communicate with the water legs 2Ia and 2lb respectively.

As best shown in Figure 2, the tubes 26 are in staggered relation and are spaced to baille the flow of llames and gases therearound.

The rear plates I2 and I6 have aligned openings 21 and 28 therethrough intermediate the tops and bottoms of the plates behind the baille 23 and preferably below the top of the baille. A collar 29 is welded in the openings 2'I and 28 and extends between the plates. The collar 29 is adapted to receive the end of a flue pipe 30 therein. This construction provides a smoke outlet for the combustion chamber 22.

The inner and outer front plates I5 and II have large openings 3| therethrough above the flange I8 of the inner plate. A steel ring 32 is welded between the openings 3| to the plates. This construction provides a port to the combustion chamber 22 which port can be closed by a iire door 33.

In the embodiment of the invention shown in Figure 1 an oil burner head 34 is mounted in the combustion chamber in front of the baille 23. The lower portion of the combustion chamber around the burner head 34 can be insulated with iire bricks such as 35.

The oil supply line 36 can extend into the combustion chamber 22 through an opening 31 cut in the bottom of the front plate II.

It should be understood, however, that the combustion chamber 22 can receive any type of heating means such as a gas burner, a stoker, or a grate. An important feature of this boiler is the provision of a combustion chamber 22 adapted to receive any type of heating means. Of course, various fire b-rick arrangements can be used without in any way changing the boiler construction.

Flanged openings such as 38 are formed through the outer shell to receive inlet and return pipes (not shown) or clean out plugs (not shown). The top of the crown sheet I4 contains a steam outlet 39.

In accordance with good boiler practice, the water level is maintained above the crown sheet I9 but below the steam outlet 39.

The lower portion of the combustion chamber behind the baille 23 provides a natural trap for soot, and ily ash. Since the flames travel upwardly from the burner head or fuel bed, around the boiler tubes 26, over the baille 23 and downwardly to the smoke outlet 30, entrained solid material can be collected in the space behind the baffle 23. A clean out door 40 is provided on the crown sheet I4 at the bottom thereof for cleaning out this space.

As best shown in Figure 4 the llames 4I in the combustion chamber will flow around a streamlined tear-drop type boiler tube 26 to be in extended contact with the tube over almost the entire exterior area thereof. In other words the flow of the flames as shown in dotted lines around the boiler tube 26 follows the contour of the tube. This extended contact between the ilames and the boiler tube gives an excellent heat transfer for heating water in the tube.

On the other hand the commonly used cylindrical type tube, indicated by the reference numeral 42, can only contact the flames 4I around the lower half thereof.

Therefore the streamlined boiler tubes used in the construction of this invention are more efficient heat exchangers than ordinary cylindrical or other non-streamline shaped tubes.

It should be noted also that the top portions of cylindrical tubes provide surfaces for the collecting of soot, ily ash and the like. These surfaces are entirely dispensed with in the stream* lined tubes. As a result, the boilers of this invention are substantially self-cleaning whereas heretofore it has been necessary to clean the water tubes of boilers at frequent intervals.

I am aware that many changes may be made and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I, therefore, do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.

I claim as my invention:

l. A boiler construction comprising spaced opposed front and rear outer plates, an outer metal sheet welded to the tops and sides of said outer plates, front and rear inner plates each spaced from their cooperating outer plates to dei-lne Water legs therebetween at the ends of the boiler. an inner metal sheet welded to the tops and sides of said inner plates and spaced from the outer metal sheet to define therewith a water space on the top and water legs on the sides of the boiler, said inner plates having a plurality of tear-drop shaped apertures therethrough near the tops thereof, a plurality of tear-drop shaped boiler tubes secured at their ends in said opertures to be in full communication with the water legs, a hollow baille extending transversely between the sides of the inner metal sheet having the interior thereof communicating with the water legs at the sides of the boiler, the top of the baille being below the top of the inner metal sheet, a smoke outlet at the rear of the boiler in spaced relation behind said baille at a level intermediate the top and bottom of the baille, the rear inner plate and rear wall of the baille defining with the inner metal sheet a ily ash chamber and a door giving access to said chamber.

2. A boiler construction comprising spaced opposed front and rear outer plates, an outer metal sheet secured to the tops and sides of said outer plates, front and rear inner plates each spaced from their cooperating outer plates to define water legs therebetween at the ends of the boiler, an inner metal sheet secured to the tops and sides of said inner plates and spaced from the outer metal sheet to define therewith a water space on the top and water legs on the sides of the boiler, said inner plates having a plurality of tear drop shaped apertures therethrough, a plurality of tear drop shaped boiler tubes secured at their ends in said apertures to be in full communication with the water legs, a baffle extending transversely between the sides of the inner metal sheet in spaced relation from the front and rear inner plates, said baiile terminating below the top of the inner metal sheet, a smoke outlet at the rear of the boiler in spaced relation behind said baille and communicating with the interior of the boiler at a level intermediate the top and bottom of the baiiie, said rear inner plate and rear Wall of the baffle defining with the inner metal sheet, a fly ash chamber, and clean out means giving access to said ily ash chamber.

3. A boiler construction comprising spaced op-` posed front and rear outer plates, an outer metal sheet secured to the tops and sides .of said outer plates, front and rear inner plates each spaced from their cooperating outer plates to deiine water legs therebetween at the ends of the boiler, an inner metal sheet secured to the tops and sides of said inner plates and spaced from the outer metal sheet to dene therewith a water space on the top and water legs on the sides of the boiler, said inner plates having a plurality of apertures therethrough, a plurality of water tubes secured at their ends in said apertures to be in communication with the water legs, a hollow baffle extending transversely between the sides of the inner metal sheet in spaced relation from the front and rear inner plates and having the interior thereof communicating with the water legs at the sides of the boiler, the top of the baie being below the top of the inner metaly sheet, a smoke outlet at the rear of the boiler in spaced relation behind said baiile and communicating with the boiler at a level intermediate the top and bottom of the baiile, said rear inner plate and the rear Wall of the baille dening with said inner metal sheet a fly ash chamber and a clean out means giving access to said chamber.

WILLIAM J. MCALLISTER. 

